| 摘要 |
PROBLEM TO BE SOLVED: To provide an air-conditioning-duct fire damper exhibiting three-hour fire-resistance performance so as to comply with new safety standards for nuclear power plant facilities. ! SOLUTION: In an air-conditioning-duct fire damper 1 including: a cylindrical casing 2; one or a plurality of damper shafts 3 provided in the casing 2; opening/closing blades 4 that are fixedly provided on the damper shaft or damper shafts 3 and that can open/close a channel in response to rotation of the damper shaft or damper shafts 3; and a damper automatic normally closing mechanism 5 keeping the opening/closing blades 4 closed and automatically closing the opening/closing blades 4 at a time of detecting a temperature indicating a fire, a clearance A is formed in a bearing device 6 of each damper shaft 3 so as not to hamper thermal expansion of the damper shaft 3, a gap K is formed between each end of the opening/closing blades 4 and an inner surface of the casing 2, and a liner member 10 closing the gap K |
